Thin film transistor substrate, liquid crystal panel and liquid crystal display device using the same

ABSTRACT

A thin film transistor (TFT) substrate including a base, a plurality of scan lines and data lines and a pixel unit is provided. The scan lines are disposed on the base. The data lines are disposed above the scan lines and are perpendicular to the scan lines to define a plurality of pixel areas. The pixel unit is disposed on the base and inside one of the pixel areas. The pixel unit comprises a TFT and a pixel electrode. The TFT comprises a source and a drain. The pixel electrode is electrically connected to the drain. The pixel electrode comprises a first main electrode, a second main electrode and a plurality of branch electrodes. The first main electrode is perpendicular to the second main electrode. The branch electrodes are connected to the first main electrode and/or the second main electrode. The first main electrode substantially divides the pixel area evenly.

This application is a continuation application of U.S. patentapplication Ser. No. 11/526,706, filed on Sep. 26, 2006, which claimsthe benefit of Taiwan Patent Application Serial No. 95124706, filed Jul.6, 2006, the subject matter of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates in general to a thin film transistor (TFT)substrate, a liquid crystal panel and a liquid crystal display (LCD)device using the same, and more particularly to a TFT substrate having apolymer stabilized alignment layer.

2. Description of the Related Art

The liquid crystal display (LCD) technology has made rapid progress inrecent years, and factors crucial to the quality of an LCD device suchas response time, view-angle and brightness are continually improved.

Referring to FIG. 1, a diagram of a TFT substrate is shown. In the pixelunit 10, the through hole connected to the TFT 4 is disposed on thecommon electrode 2, and is connected to the common electrode 2 by theconducting wire 1 a of the second metal layer 1 (M2) along the mainelectrode 3 a of the pixel electrode 3, such that the aperture rate isincreased. However, repair becomes very difficult when breakage occursto the second metal layer 1. The TFT 4 is positioned at a corner of thepixel unit 10, and the conducting wire 1 a has to bend to pass throughthe pixel electrode 3. If mismatch occurs between the pixel electrode 3and the second metal layer 1, overlapping will cause the aperture rateto decrease, further reducing the brightness of the pixel unit. To theworse, during the UV-light exposing process of forming a polymeralignment layer, the change in electrical field effect will affect thearrangement of liquid crystals and result in disclination line.

Besides, precision requirement has to be satisfied when matching theblack matrix (BM) of the color filter substrate on the top layer withthe TFT substrate on the bottom layer, so the design of pixel has totake the precision requirement of the manufacturing process intoaccount. If mismatch occurs during assembly, the aperture rate isdecreased and the brightness is reduced, and the arrangement of liquidcrystal will be affected and disclination line will occur.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a thin filmtransistor (TFT) substrate, a liquid crystal panel and a liquid crystaldisplay (LCD) device using the same. A new pixel structure is formed bydesigning different pixel electrode patterns and changing the positionof the through hole.

The invention achieves the above-identified object by providing a thinfilm transistor (TFT) substrate. The TFT substrate comprising a base, aplurality of scan lines and data lines and a pixel unit is provided. Thescan lines are disposed on the base. The data lines are disposed abovethe scan lines and are perpendicular to the scan lines to define aplurality of pixel areas. The pixel unit is disposed on the base andinside one of the pixel areas. The pixel unit comprises a TFT and apixel electrode. The TFT comprises a source and a drain. The pixelelectrode is electrically connected to the drain. The pixel electrodecomprises a first main electrode, a second main electrode and aplurality of branch electrodes. The first main electrode isperpendicular to the second main electrode. The branch electrodes areconnected to the first main electrode and/or the second main electrode.The first main electrode substantially divides the pixel area evenly.The TFT substantially corresponds to one end of the first mainelectrode.

The invention further achieves the above-identified object by providinga liquid crystal (LC) panel. The liquid crystal panel comprises a firstsubstrate, a second substrate and a liquid crystal layer. The secondsubstrate is disposed under the first substrate. The second substratecomprises a base, a plurality of scan lines, a plurality of data linesand a pixel unit. The scan lines are disposed on the base. The datalines are disposed above the scan lines and are perpendicular to thescan lines to define a plurality of pixel areas. The pixel unit isdisposed on the base and inside one of the pixel areas. The pixel unitcomprises a TFT and a pixel electrode. The TFT comprises a source and adrain. The pixel electrode is electrically connected to the drain. Thepixel electrode comprises a first main electrode, a second mainelectrode and a plurality of branch electrodes. The first main electrodeis perpendicular to the second main electrode. The branch electrodes areconnected to the first main electrode and/or the second main electrode,the first main electrode substantially divides the pixel area evenly.The TFT substantially corresponds to one end of the first mainelectrode. The liquid crystal layer is sealed between the firstsubstrate and the second substrate.

The invention further achieves the above-identified object by providinga liquid crystal display (LCD). The LCD comprises a first substrate, asecond substrate, a liquid crystal layer and a backlight module. Thesecond substrate is disposed under the first substrate. The secondsubstrate comprises a base, a plurality of scan lines, a plurality ofdata lines and a pixel unit. The scan lines are disposed on the base.The data lines are disposed above the scan lines and are perpendicularto the scan lines to define a plurality of pixel areas. The pixel unitis disposed on the base and inside one of the pixel areas. The pixelunit comprises a TFT and a pixel electrode. The TFT comprises a sourceand a drain. The pixel electrode is electrically connected to the drain.The pixel electrode comprises a first main electrode, a second mainelectrode and a plurality of branch electrodes. The first main electrodeis perpendicular to the second main electrode. The branch electrodes areconnected to the first main electrode and/or the second main electrode,the first main electrode substantially divides the pixel area evenly.The TFT substantially corresponds to one end of the first mainelectrode. The liquid crystal layer is sealed between the firstsubstrate and the second substrate. The backlight module is disposedunder the second substrate.

Other objects, features, and advantages of the invention will becomeapparent from the following detailed description of the preferred butnon-limiting embodiments. The following description is made withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (Related Art) is a diagram of a TFT substrate;

FIG. 2 is a diagram of an LCD panel having a polymer alignment layer;

FIG. 3A is a partial diagram of a TFT substrate of a first embodiment;

FIG. 3B is a diagram of the first pixel unit of a first embodiment;

FIG. 3C is a cross-sectional view along the cross-sectional line AA′ofFIG. 3B;

FIG. 3D is a diagram of the second pixel unit of a first embodiment;

FIG. 3E is a diagram of the third pixel unit of a first embodiment;

FIG. 3F is a diagram of the fourth pixel unit of a first embodiment;

FIG. 3G is a diagram of the fifth pixel unit of a first embodiment;

FIG. 3H is a diagram of the sixth pixel unit of a first embodiment;

FIG. 4A is a diagram of the first pixel unit of a second embodiment;

FIG. 4B is a cross-sectional view along the cross-sectional line AA′ ofFIG. 4A;

FIG. 4C is another cross-sectional view along the cross-sectional lineAA′ of FIG. 4A;

FIGS. 4D˜4F respectively illustrate the second pixel unit to the fourthpixel unit of a second embodiment;

FIG. 5A is a diagram of the first pixel unit of a third embodiment;

FIG. 5B is a cross-sectional view along the cross-sectional line AA′ ofFIG. 5A;

FIGS. 5C˜5E respectively illustrate the second pixel unit to the fourthpixel unit of a third embodiment;

FIG. 6A is a diagram of the first pixel unit of a fourth embodiment;

FIG. 6B is a cross-sectional view along the cross-sectional line AA′ ofFIG. 6A;

FIG. 6C is another cross-sectional view along the cross-sectional lineAA′ of FIG. 6A; and

FIGS. 6D˜6F respectively illustrate the second pixel unit to the fourthpixel unit of a fourth embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 2, a diagram of an LCD panel having a polymeralignment layer is shown. Examples of the liquid crystal display (LCD)panel having a polymer alignment layer include the LCD panel formedaccording to the polymer stabilized alignment (PSA) technology. The LCD100 includes a first substrate 110, a second substrate 130, a liquidcrystal layer 120 and a backlight module 138. The second substrate 130is disposed under the first substrate 110. The second substrate 130includes a base 132. The TFT layer 134 is disposed on the base 132. Theliquid crystal layer 120 is sealed between the first substrate 110 andthe second substrate 130. The backlight module 138 is disposed under thesecond substrate 130. The liquid crystal layer 120 further includes anumber of reactive monomers (not illustrated) and a number of liquidcrystal molecules 124. The reactive monomers are polymerized by lightexposing or heating to form the polymers for aligning the liquid crystalmolecules such that an alignment structure 122 is formed on the innersurfaces of the first substrate 110 and the second substrate 130. Thefirst substrate 110 is a color filter substrate. The second substrate130 is a TFT substrate. A first polarizer 116 and a second polarizer 136are respectively pasted on the first substrate 110 and the secondsubstrate 130. The polarizing direction of the first polarizer 116 isperpendicular to that of the second polarizer 136.

First Embodiment

Referring to FIG. 3A, a partial diagram of a TFT substrate of a firstembodiment is shown. The second substrate 130 comprises a base 132, anumber of scan lines 131, a number of data lines 133 and a pixel unit140. The scan lines 131 are disposed on the base 132. The data lines 133are disposed above the scan lines 131. The data lines 133 areperpendicular to the scan lines 131 to define a number of pixel areas135. The pixel unit 140 is disposed on the base 132 and inside one ofpixel areas 135. Referring to FIG. 3B, a diagram of the first pixel unitof a first embodiment is shown. The scan lines 131 of FIG. 3A include afirst scan line 131 a and a second scan line 131 b. The data lines 133of FIG. 3A include a first data line 133 a and a second data line 133 b.The pixel unit 140 includes a TFT 141 and a pixel electrode 142. The TFT141 includes a source 141 a, a drain 141 b and a gate (not illustrated).The pixel electrode 142 is electrically connected to the drain 141 b.The pixel electrode 142 includes a first main electrode 142 a, a secondmain electrode 142 b and a number of branch electrodes 142 c. The firstmain electrode 142 a is perpendicular to the second main electrode 142b. The branch electrodes 142 c are connected to the first main electrode142 a or the second main electrode 142 b. The first main electrode 142 asubstantially divides the pixel area 135 evenly. The TFT 141substantially corresponds to one end of the first main electrode 142 a.In the present embodiment of the invention, the first main electrode 142a is substantially extended to pass through the center of the TFT 141.That is, the TFT 141 is positioned in the middle of the scan line 131 aand the scan line 131 b in pixel area 135.

The branch electrodes 142 c respectively form an acute angle with thefirst main electrode 142 a and the second main electrode 142 b. Thebranch electrodes 142 c are distributed on the two sides of the firstmain electrode 142 a and the second main electrode 142 b. In the presentembodiment of the invention, the branch electrodes 142 c aresymmetrically disposed with respect to the first main electrode 142 aand the second main electrode 142 b.

Referring to both FIG. 3B and FIG. 3C. FIG. 3C is a cross-sectional viewalong the cross-sectional line AA′of FIG. 3B. The TFT substrate 130further includes at least a first electrode 143, a first insulatinglayer 144, a second electrode 145 and a second insulating layer 146. Thechannel 141 c is disposed on the first insulating layer 144. The source141 a and the drain 141 b are inter-spaced and disposed on the channel141 c. The first electrode 143 is disposed on the base 132 andpositioned between the first scan line 131 a and the second scan line131 b. The first insulating layer 144 covers the first scan line 131 a,the second scan line 131 b and the first electrode 143. The first dataline 133 a and the second data line 133 b are respectively perpendicularto the first scan line 131 a and the second scan line 131 b and aredisposed on the first insulating layer 144.

The pixel electrode 142 is positioned between the first data line 133 aand the second data line 133 b. The second electrode 145 is disposed onthe first insulating layer 144 and positioned on the first electrode 143to form a storage capacitor 147 with the first electrode 143. The secondinsulating layer 146 is disposed between the pixel electrode 142 and thefirst data line 133 a, the second data line 133 b, the TFT 141, and thesecond electrode 145. The pixel electrode 142 is electrically connectedto the second electrode 145 via a first through hole 146 a of the secondinsulating layer 146. In the present embodiment of the invention, thedrain 141 b further comprises an extending portion 141 d electricallyconnected to the second electrode 145, such that the drain 141 b and thesecond electrode 145 have the same potential. Since the TFT 141 isopposite to the first main electrode 142 a, the extending portion 141 dof the drain 141 b can be electrically connected to the second electrode145 via the first through hole 146 a along the first main electrode 142a. The position of the first main electrode 142 a is a non-transparentarea; therefore such pixel structure will not affect the aperture rate.

Referring to FIG. 3D, a diagram of the second pixel unit of a firstembodiment is shown. As for the elements similar to FIG. 3B, the samereference numbers are used and descriptions are not repeated here. Thebranch electrodes 152 c are alternately disposed on the two sides of thefirst main electrode 141 a and the second main electrode 141 b as shownin FIG. 3D. Such pixel electrode structure allows the liquid crystalmolecules to be more evenly distributed and concentrated towards thefirst main electrode 141 a and the second main electrode 141 b toincrease the aperture rate.

Referring to FIG. 3E, a diagram of the third pixel unit of a firstembodiment is shown. As for the elements similar to FIG. 3B, the samereference numbers are used and descriptions are not repeated here. Thepixel electrode 162 includes a frame electrode 164. The first mainelectrode 142 a, the second main electrode 142 b and the branchelectrodes 142 c are positioned inside the frame electrode 164 andconnected to the frame electrode 164. The disposition of the frameelectrode 164 expands the distribution of the liquid crystal moleculessurrounding the pixel electrode 162 and increases the aperture rate.

Referring to FIG. 3F, a diagram of the fourth pixel unit of a firstembodiment is shown. As for the elements similar to FIG. 3D, the samereference numbers are used and descriptions are not repeated here. Thepixel electrode 172 includes a frame electrode 164. The pixel electrode172 includes the branch electrodes 152 c alternately arranged and theframe electrode 164 such that the aperture rate is increased.

Referring to FIG. 3G, a diagram of the fifth pixel unit of a firstembodiment is shown. In the pixel unit 180, the frame electrode 184 ofthe pixel electrode 182 has a gap 184 a above the first electrode 143.As for other elements similar to FIG. 3E, the same reference numbers areused and descriptions are not repeated here. Since the first electrode143 is positioned at a non-transparent area, the frame electrode 184 hasless influence at the position of the first electrode 143.

Referring to FIG. 3H, a diagram of the sixth pixel unit of a firstembodiment is shown. In the pixel unit 190, the frame electrode 184 ofthe pixel electrode 192 includes a gap 184 a above the first electrode143. As for other elements similar to FIG. 3F, the same referencenumbers are used and descriptions are not repeated here. Since the firstelectrode 143 is positioned at a non-transparent area, the frameelectrode 184 has less influence at the position of the first electrode143.

Second Embodiment

Referring to FIG. 4A, a diagram of the first pixel unit of a secondembodiment is shown. The structures of the black matrix layer 220 andthe color filter layer 230 are disposed on the TFT substrate as shown inFIG. 4B. Referring to FIG. 4B, a cross-sectional view along thecross-sectional line AA′ of FIG. 4A is shown. As for other elementssimilar to FIG. 3E and FIG. 3C, the same reference numbers are used anddescriptions are not repeated here. A protection layer 240 is disposedon the second insulating layer 146 and pixel electrode 162. The colorfilter layer 230 and the black matrix layer 220 are disposed on theprotection layer 240. The present embodiment of the inventionincorporates the structure of the pixel unit with the color filter onarray (COA) manufacturing process and disposes the black matrix layer220 and the color filter layer 230 on the TFT substrate. Therefore, whenthe top substrate and the bottom substrate are matched, the aperturerate will not be decreased due to the shift of the black matrix layer220 caused by mismatch or misalignment.

Referring to FIG. 4C, another cross-sectional view along thecross-sectional line AA′ of FIG. 4A is shown. Between the base 132 andthe first scan line 131 a, the second scan line 131 b, and the firstelectrode 143, there are a color filter layer 230 and a black matrixlayer 220 disposed on the base 132. The protection layer 240 is disposedon the color filter layer 230 and the black matrix layer 220. The firstscan line 131 a, the second scan line 131 b and the first electrode 143are disposed on the protection layer 240. The present embodiment of theinvention incorporates the pixel unit structure with the array on colorfilter (AOC) manufacturing process lest the aperture rate might bedecreased due to the shift of the black matrix layer 220 caused bymismatch.

Referring to FIGS. 4D˜4F, the second pixel unit to the fourth pixel unitof a second embodiment are respectively illustrated. In the pixel unit250, 260 and 270 of FIG. 4D, FIG. 4E and FIG. 4F, the structures of theblack matrix 220 and the color filter layer 230 are disposed on the TFTsubstrate. As for other elements whose connections and functions remainthe same, the same reference numbers are used and descriptions are notrepeated here.

Third Embodiment

Referring to FIG. 5A, a diagram of the first pixel unit of a thirdembodiment is shown. In the pixel unit 310 of the present embodiment ofthe invention, the structures of the black matrix 220 and the colorfilter layer 230 are disposed on the first substrate 110 as shown inFIG. 2. Referring to FIG. 5B, a cross-sectional view along thecross-sectional line AA′ of FIG. 5A is shown. As for other elementssimilar to FIG. 3E and FIG. 3C, the same reference numbers are used anddescriptions are not repeated here. As shown in FIG. 5B, the drain 141 bis electrically connected to the pixel electrode 312 via the secondthrough hole 146 b. The pixel electrode 312 is further electricallyconnected to the second electrode 145 via the first through hole 146 a,such that the drain 141 b and the second electrode 145 have the samepotential. The above structure prevents the aperture rate from beingaffected when shift occurs between the second metal layer and the pixelelectrode.

Referring to FIGS. 5C˜5E, the second pixel unit to the fourth pixel unitof a third embodiment are respectively illustrated. In the pixel units320, 330 and 340 of FIGS. 5C˜5E, the pixel electrodes 322, 332, and 342respectively have a second through hole 146 b, and the drain 141 b iselectrically connected to the pixel electrodes 322, 332, 342 via thesecond through hole 146 b. The pixel electrodes 322, 332, and 342 arefurther electrically connected to the second electrode 145 via the firstthrough hole 146 a, such that the drain 141 b and the second electrode145 have the same potential. As for other elements whose connections andfunctions are similar to the pixel units 170, 180 and 190 of FIGS.3F˜3H, the same reference numbers are used and descriptions are notrepeated here.

Fourth Embodiment

Referring to FIG. 6A, a diagram of the first pixel unit of a fourthembodiment is shown. In the pixel unit 410 of the present embodiment ofthe invention, the structures of the black matrix layer 220 and thecolor filter layer 230 are disposed on the TFT substrate as shown inFIG. 6B. Referring to FIG. 6B, a cross-sectional view along thecross-sectional line AA′ of FIG. 6A is shown. As for other elementssimilar to FIG. 5A and FIG. 5B, the same reference numbers are used anddescriptions are not repeated here. As shown in FIG. 6B, a protectionlayer 240 is disposed on the second insulating layer 146 and pixelelectrode 312. The color filter layer 230 is disposed on the protectionlayer 240. The black matrix layer 220 is disposed on the protectionlayer 240. According to the present embodiment of the invention, thepixel unit structure incorporated with the COA manufacturing process todispose the black matrix layer 220 and the color filter layer 230 on theTFT substrate. Thus, when the top substrate and the bottom substrate arematched, the aperture rate will not be reduced due to the shift of theblack matrix layer 220 caused by mismatch.

Referring to FIG. 6C, another cross-sectional view along thecross-sectional line AA′ of FIG. 6A is shown. Between the base 132 andthe first scan lines 131 a, the second scan lines 131 b, and the firstelectrode 143, there are a color filter layer 230 and a black matrixlayer 220 disposed on the base 132. The protection layer 240 is disposedon the color filter layer 230 and the black matrix layer 220. The firstscan line 131 a, the second scan line 131 b and the first electrode 143are disposed on the protection layer 240. According to the presentembodiment of the invention, the pixel unit structure is incorporatedwith the AOC manufacturing process, such that the aperture rate will notbe reduced due to the shift of the black matrix layer 220 caused bymismatch.

Referring to FIGS. 6D˜6F, the second pixel unit to the fourth pixel unitof a fourth embodiment are respectively illustrated. In the pixel unit420, 430 and 440 of FIGS. 6D˜6F, the structures of the black matrix 220and the color filter layer 230 are disposed on the TFT substrate. As forother elements whose connections and functions are similar to the pixelunits 320, 330 and 340 of FIGS. 5C˜5E, the same reference numbers areused and descriptions are not repeated here.

According to the TFT substrate and the LCD device using the samedisclosed in the above embodiments of the invention, the TFT iscorrespondingly disposed on one end of the first main electrode forenabling the extending portion of the drain to be electrically connectedto the second electrode along the first main electrode without passingthrough the transparent area, such that the aperture rate is notaffected. Alternatively, a second through hole can be disposedneighboring to the TFT and above the second insulating layer, such thatthe drain and the second electrode are directly connected to have thesame potential via the pixel electrode and, lest the aperture rate mightbe affected due to the shift of the second metal layer. Furthermore, theCOA or the AOC manufacturing process can be incorporated to dispose theblack matrix layer and the color filter layer on the TFT substrate, suchthat the aperture rate will not be reduced when the substrates aremismatched.

While the invention has been described by way of example and in terms ofpreferred embodiments, it is to be understood that the invention is notlimited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

1. A thin film transistor (TFT) substrate, comprising: a base; aplurality of scan lines disposed on the base; a plurality of data linesdisposed on the base; and a pixel unit disposed on the base, wherein thepixel unit comprises: a thin film transistor, comprising a source and adrain; and a pixel electrode electrically connected to the drain via aconnecting portion, wherein the pixel electrode comprises a first mainelectrode, a second main electrode and a plurality of branch electrodes,the branch electrodes being connected to the first main electrode and/orthe second main electrode, and wherein the connection portion and thebranch electrodes are substantially not overlapped; wherein the scanlines comprise a first scan line and a second scan line, the data linescomprise a first data line and a second data line, and the TFT substratefurther comprises: at least a first electrode disposed on the base andpositioned between the first scan line and the second scan line; a firstinsulating layer covering the first scan line, the second scan line andthe first electrode, wherein the first data line and the second dataline are respectively perpendicular to the first scan line and thesecond scan line and are disposed on the first insulating layer, and thepixel electrode is positioned between the first data line and the seconddata line; a second electrode disposed on the first insulating layer andpositioned on the first electrode to form a storage capacitor with thefirst electrode; and a second insulating layer, having at least onefirst through hole, disposed between the pixel electrode and the firstdata line, the second data line, the thin film transistor, and thesecond electrode, wherein the pixel electrode is connected to the secondelectrode via the at least one first through hole of the secondinsulating layer.
 2. The TFT substrate according to claim 1, wherein thebranch electrodes form an acute angle with the first main electrode. 3.The TFT substrate according to claim 1, wherein: the branch electrodesare distributed on two sides of the first main electrode; and the branchelectrodes are symmetrically disposed with respect to the first mainelectrode.
 4. The TFT substrate according to claim 1, wherein: thebranch electrodes are distributed on two sides of the first mainelectrode; and the branch electrodes are alternately disposed on twosides of the first main electrode.
 5. The TFT substrate according toclaim 1, wherein the pixel electrode further comprises a frameelectrode; the first main electrode, the second main electrode and thebranch electrodes are positioned inside the frame electrode andconnected to the frame electrode; and wherein the frame electrodecomprises at least a gap above the first electrode.
 6. The TFT substrateaccording to claim 1, wherein the second insulating layer further has asecond through hole, and the drain is electrically connected to thepixel electrode via the second through hole such that the drain iselectrically connected to the second electrode.
 7. The TFT substrateaccording to claim 1, further comprising: a protection layer disposed onthe second insulating layer and the pixel electrode; at least a colorfilter layer disposed on the protection layer; and a black matrix layerdisposed on the protection layer.
 8. The TFT substrate according toclaim 1, further comprising: at least a color filter layer disposed onthe base; a protection layer disposed on the color filter layer, whereinthe first scan line, the second scan line and the first electrode aredisposed on the protection layer; and a black matrix layer disposed onthe base, wherein the protection layer covers the black matrix layer. 9.The TFT substrate according to claim 1, further comprising an alignmentlayer disposed on the pixel electrode, wherein the alignment layer isformed by a plurality of polymers.
 10. The TFT substrate according toclaim 1, wherein the connecting portion and the first main electrode areoverlapped.
 11. The TFT substrate according to claim 1, wherein theconnecting portion is substantially shielded by the first mainelectrode.
 12. The TFT substrate according to claim 1, wherein theconnecting portion and the second main electrode are not overlapped. 13.A thin film transistor (TFT) substrate, comprising: a base; a pluralityof scan lines disposed on the base; a plurality of data lines disposedon the base; and a pixel unit disposed on the base, wherein the pixelunit comprises: a thin film transistor, comprising a source and a drain;and a pixel electrode electrically connected to the drain via a contacthole, wherein the pixel electrode comprises a first main electrode, asecond main electrode and a plurality of branch electrodes, the branchelectrodes being connected to the first main electrode and/or the secondmain electrode, wherein the contact hole is located adjacent to an edgeof the pixel electrode; wherein the scan lines comprise a first scanline and a second scan line, the data lines comprise a first data lineand a second data line, and the TFT substrate further comprises: atleast a first electrode disposed on the base and positioned between thefirst scan line and the second scan line; a first insulating layercovering the first scan line, the second scan line and the firstelectrode, wherein the first data line and the second data line arerespectively perpendicular to the first scan line and the second scanline and are disposed on the first insulating layer, and the pixelelectrode is positioned between the first data line and the second dataline; a second electrode disposed on the first insulating layer andpositioned on the first electrode to form a storage capacitor with thefirst electrode; and a second insulating layer, having at least onefirst through hole, disposed between the pixel electrode and the firstdata line, the second data line, the thin film transistor, and thesecond electrode, wherein the pixel electrode is connected to the secondelectrode via the at least one first through hole of the secondinsulating layer.
 14. The TFT substrate according to claim 13, whereinthe branch electrodes form an acute angle with the first main electrode.15. The TFT substrate according to claim 13, wherein the pixel electrodefurther comprises a frame electrode; the first main electrode, thesecond main electrode and the branch electrodes are positioned insidethe frame electrode and connected to the frame electrode; and the frameelectrode comprises at least a gap above the first electrode.
 16. TheTFT substrate according to claim 13, further comprising: a protectionlayer disposed on the second insulating layer and the pixel electrode;and at least a color filter layer disposed on the protection layer. 17.The TFT substrate according to claim 13, further comprising an alignmentlayer disposed on the pixel electrode, wherein the alignment layer isformed by a plurality of polymers.
 18. A liquid crystal panel,comprising: a first substrate; a second substrate disposed under thefirst substrate, comprising: a base; a plurality of scan lines disposedon the base; a plurality of data lines disposed on the base; and a pixelunit disposed on the base, the pixel unit comprising: a thin filmtransistor (TFT) comprising a source and a drain; and a pixel electrodeelectrically connected to the drain via a connecting portion, whereinthe pixel electrode comprises a first main electrode, a second mainelectrode and a plurality of branch electrodes, the branch electrodesbeing connected to the first main electrode and/or the second mainelectrode, and wherein the connection portion and the branch electrodesare substantially not overlapped; and a liquid crystal layer sealedbetween the first substrate and the second substrate; wherein the scanlines comprise a first scan line and a second scan line, the data linescomprise a first data line and a second data line, and the secondsubstrate further comprises: at least a first electrode disposed on thebase and positioned between the first scan line and the second scanline; a first insulating layer covering the first scan line, the secondscan line and the first electrode, wherein the first data line and thesecond data line are respectively perpendicular to the first scan lineand the second scan line and are disposed on the first insulating layer,and the pixel electrode is positioned between the first data line andthe second data line; a second electrode disposed on the firstinsulating layer and positioned on the first electrode to form a storagecapacitor with the first electrode; and a second insulating layer,having at least one first through hole, disposed between the pixelelectrode and the first data line, the second data line, the thin filmtransistor, and the second electrode, wherein the pixel electrode isconnected to the second electrode via the at least one first throughhole of the second insulating layer.
 19. A liquid crystal panel,comprising: a first substrate; a second substrate disposed under thefirst substrate, comprising: a base; a plurality of scan lines disposedon the base; a plurality of data lines disposed on the base; and a pixelunit disposed on the base, the pixel unit comprising: a thin filmtransistor (TFT) comprising a source and a drain; and a pixel electrodeelectrically connected to the drain via a contact hole, wherein thepixel electrode comprises a first main electrode, a second mainelectrode and a plurality of branch electrodes, the branch electrodesbeing connected to the first main electrode and/or the second mainelectrode, wherein the contact hole is located adjacent to an edge ofthe pixel electrode; and a liquid crystal layer sealed between the firstsubstrate and the second substrate; wherein the scan lines comprise afirst scan line and a second scan line, the data lines comprise a firstdata line and a second data line, and the second substrate furthercomprises: at least a first electrode disposed on the base andpositioned between the first scan line and the second scan line; a firstinsulating layer covering the first scan line, the second scan line andthe first electrode, wherein the first data line and the second dataline are respectively perpendicular to the first scan line and thesecond scan line and are disposed on the first insulating layer, and thepixel electrode is positioned between the first data line and the seconddata line; a second electrode disposed on the first insulating layer andpositioned on the first electrode to form a storage capacitor with thefirst electrode; and a second insulating layer, having at least onefirst through hole, disposed between the pixel electrode and the firstdata line, the second data line, the thin film transistor, and thesecond electrode, wherein the pixel electrode is connected to the secondelectrode via the at least one first through hole of the secondinsulating layer.